Handrail for escalators, moving walkways and the like and a process for its production

ABSTRACT

Handrails for escalators, moving walkways and the like consist of an endless, flexible strip (1) with a gripping region (2) and guiding regions (4) which, in operation, slide on a fixed guideway, and steel cables which are embedded in the strip (1) and serve as tensile supports. In order to be able to produce the handrails more simply and with less outlay, the strip (1) is divided in its longitudinal direction into individual segments (5, 6, 7) which follow closely upon one another, the segments being molded firmly around the steel cable (3). The segments can be injection molded around the steel cables (3), a thermoplastic elastomer being used.

BACKGROUND OF THE INVENTION

The invention relates to a handrail for escalators, moving walkways andthe like, comprising an endless, flexible strip with a gripping regionand a guiding region which, in operation, slide on a fixed guideway, andone or more tensile supports embedded in the strip and consisting ofhigh-strength materials with limited extensibility and to a process forits production.

Known handrails of the said type consist of continuous endless strips ofnatural or synthetic rubber with incorporated reinforcing layers.Although these known handrails have given excellent results inoperation, their production is extremely complicated. The knownhandrails are produced in the form of full-length handrails or in longlengths and must then be vulcanized length by length, for which purposethey must each be processed in a vulcanization press. After vulcanizing,the handrail is joined together to form an endless loop in a relativelycomplicated and not always satisfactory manner.

Furthermore, so-called link-type handrail strips are known, which aremade up of individual elements of the same cross-section. In thisarrangement, the elements are either connected to one another directly(German Patent Specification 1,811,982) or are mounted on a common,continuous drag chain (U.S. Pat. No. 2,766,886). The disadvantage of theknown link-type handrail strips consists in the fact that they exhibitexcessively high elongation in the direction of running since the playbetween each pair of elements due to the production and assembly methodsadds up cumulatively over the whole length to an impermissibly largeplay. This is particularly the case with wear after prolonged runningand is noticeable by a sharp rise in the running noise. A furtherdisadvantage is the wear which arises due to the friction between theindividual elements and the guide rails.

From U.S. Pat. No. 2,778,882 a handrail is known which is made up ofplastic bodies and an endless covering of elastic plastics material orrubber. The basic bodies which are made of solid plastics material areindividually or in groups, formed in distance around tensile ropes. Toget a continuous condition for the covering, the mutually facing sidesof the basic bodies are supplied with projected, on space arrangedspouts.

SUMMARY OF THE INVENTION

The object on which the invention is based is to provide a handrail ofthe type stated at the outset which can be produced more simply and withlower outlay while retaining the good characteristics of previousdesigns.

This object is achieved according to the invention by the fact that thestrip is divided in its longitudinal direction into individual segments,which follow closely upon one another, and are molded firmly around thecontinuous support and the segments encircle the stationary course andare supplied with a gripping area as well as a sliding area.

The handrail according to the invention has the advantage that completesegments can be produced independently of one another in closesuccession, either individually or in groups, being molded around thecontinuous tensile support. The tensile support can thus be encapsulatedin the individual segments in the same operation in which the individualsegments are produced. As an alternative, however, it is also possibleto produce the individual segments separately beforehand and connectthem firmly to the tensile support in a second operation, for example bybonding, welding or the like. An additional continuous cover is notnecessary.

Due to the concept according to the invention, it is furthermore alsopossible for the segments forming the strip to be formed by athermoplastic elastomer. These segments can be molded around the tensilesupport by an injection molding or blow molding method. As analternative, the segments can also be produced from expandablepolyurethane using the RIM method.

The successive segments, which expediently have an approximatelyrectangular shape in plan view, can in the gripping area overlap oneanother. This ensures that the handrail is closed towards the outside,eliminating the risk of injury to the user.

The region of overlap can be formed by flat tongues which project in theaxial direction and engage in a corresponding recess of the followingsegment. The tongues extend either only in the region of the upper sideof the handrail strips or around their entire cross-section.

Each segment expediently has a flat projecting tongue at one of its endswhich extends at least over the entire width of the gripping area and arecess matched to said tongue at its other end. As a result, all thesegments consist of identical molded parts which can be produced in thesame mold or in the same group of molds.

The upper sides of the tongues are preferably in the plane of the uppersides of the segments, giving a continuously smooth surface during theoperation of the handrail strip.

In the region of the tensile support, the lower sides of the tonguesexpediently lie above said support, the good flexibility of the stripthus being retained.

In another illustrative embodiment of the handrail, the mutually facingsides of the segments in the gripping area can each be provided with aprojecting deformable flat lip, the lips resting closely against oneanother, thereby forming a continuous unbroken handrail.

With the tensile support stretched, the lips preferably rest against oneanother under prestress, providing reliably sealed interconnection ofthe gripping part.

The tensile support is expediently formed by a plurality of steel cablesextending parallel to one another. These can be arranged in one planewith mutual spacing. At least during connection to the individualsegments, the steel cables should be under pretension, thus guaranteeingthat all the steel cables provide support.

The ends of the steel cables preferably overlap one another in theirconnection region during the joining together to form an endless loop,the ends pointing in opposite directions, and are surrounded jointly byat least one segment. An externally invisible connection region isthereby created which can be produced without additional outlay. Thesegment or segments in the transition zone are produced in the samemolds as the other segments. Such a connection can be producedconsiderably more easily and to a higher standard than a vulcanizedconnection in accordance with the prior art.

In the connection region, the ends of the steel cables are expedientlyarranged adjacent to one another alternately in the same plane, with theresult that no damaging moments can arise when a tensile force isapplied.

If the segments are produced from a thermoplastic elastomer, they can beprovided in the region of their sliding surfaces with integrally moldedprojecting knobs, for example in the form of spherical caps, it therebybeing possible to reduce the frictional force in relation to the fixedguideway on which the handrail slides.

In the region of their sliding or driving surfaces, the segments can, asan alternative, also be provided with molded-in sliding or adhesivelayers, for example with textile layers, which are placed in the moldbefore the initiation of the injection molding or blow molding processor are fed in some other way.

The successive segments can be provided with a continuous covering whichoverlaps them.

The method according to the invention for producing a handrail isdistinguished by the fact that a length of the tensile support is placedin a mold, those regions of the tensile support which adjoin this lengthbeing passed through openings situated in a parting line of the mold,that in the mold, a segment being provided with a gripping area as wellas a sliding area is molded around the tensile support and, oncompletion, is removed from the opened mold together with the tensilesupport, and that a length adjoining the segment is then placed in themold and surrounded with a further segment etc.

Where the segments are of simple configuration, without undercuts, theinjection mold or blow mold can surround the respective segmentcompletely. Where the segments are of complicated configuration, withundercuts, the injection mold or blow mold can be open on the side whichfaces the adjoining, already completed segment being pulled in on thisside to close the mold and acting as part of the mold.

A very simple possibility for getting a pretension between the segmentsis to bend the tensile supports during the production of the segments.

If the method according to the invention is used, it is also readilypossible to produce a plurality of segments simultaneously in a commonmold or in separate molds arranged adjacent to one another.

If the segments are produced from a thermoplastic elastomer, the tensilesupport in the closed mold can be encapsulated by the melt of thethermoplastic elastomer.

If the tensile support consists of parallel steel cables, then afterreaching the prescribed length, the strip can be joined together to forman endless loop by placing both ends of the steel cables simultaneouslyin the mold or in a plurality of adjacent molds and embedded in asegment or a plurality of segments.

On completion of the handrail, a continuous covering can be applied tothe latter, the said covering overlapping the individual segments. Theapplication of the covering can be accomplished by producing it bycontinuous extrusion.

The invention is illustrated by way of example in the drawing anddescribed in detail below with reference to the drawing, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows, in perspective representation, a length of a handrailstrip,

FIG. 2 shows a section along the line II--II in FIG. 1 and

FIG. 3 shows a section similar to that in FIG. 2 through anotherillustrative embodiment of a handrail strip.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 of the drawing shows a short length of an endless, flexiblehandrail strip 1 provided for escalators, moving walkways or the like.

The handrail 1 has a gripping region 2 and sliding regions 4 which, inthe assembled condition of the handrail strip 1, engage around a fixedguideway (not shown in the drawing), on which the driven handrail strip1 can slide. Embedded in the upper region of the handrail strip 1 areten steel cables 3, which serve as tensile supports.

As can be seen from FIGS. 1 and 2, the handrail strip 1 is divided inits longitudinal direction into individual segments 5, 6, 7 which followclosely upon one another and have an approximately rectangular shape inplan view.

As can be seen, in particular, from FIG. 2, the successive segments 5,6, 7 overlap one another. In this arrangement, each segment 5, 6, 7 hasa projecting tongue 8 at one of its ends and a recess 9 matched to saidtongue at its other end. All the segments 5, 6, 7 are of identicaldesign. Thus, for example, the tongue 8 of segment 6 engages in therecess 9 of segment 5 while the tongue 8 of segment 7 engages in therecess 9 of segment 6.

The upper sides of the tongues 8 lie in the same plane as the uppersides 10 of the segments 5, 6, 7, i.e. on one side of the segments 5, 6,7, the tongues 8 virtually form an extension of the surface 10. Thelower sides of the tongues 8 lie above the steel cables 3.

The recesses 9 of the segments 5, 6, 7 are of step-shaped design, theheight of each step corresponding approximately to the thickness of atongue 8. The lower sides of the tongues 8 in each case rest on theupper sides of the steps of the recess 9, so that the gaps between theindividual segments 5, 6, 7 are thereby bridged.

The tongues 8 extend at least over the entire width of the gripping part2, with the result that the upper side of the handrail strip 1 is almostsmooth. However, it is also possible for the tongues 8 to extend overthe entire outward-facing region of the segments 5, 6, 7, each gap 11between the individual segments thus being covered all the way around.In that case, the recesses 9 too correspondingly extend over the entireouter region of the respective segments.

The segments 5, 6 and 7 of the illustrative embodiment of the handrailstrip 1 depicted in FIGS. 1 and 2 are manufactured from a thermoplasticelastomer. The individual segments 5, 6, 7 can accordingly be producedby an injection molding method. For this purpose, the steel cables 3 arepassed under the same pretension through openings in a correspondingmold and then, with the mold closed, encapsulated with the melt of athermoplastic elastomer. After the melt has cooled, the mold is openedand the finished segment is removed from the mold axially relative tothe pretensioned wire cables, the wire cables for the next segment beingintroduced into the mold. The operation is then repeated for as manytimes as desired. The mold is designed in such a way that the spacingbetween the segments is extremely small, each gap 11 between theindividual segments thus remaining less than 2 mm. The number of segmentcavities in the mold can vary according to the size of the injectionmolding machine. In the case of a very small injection molding machine,each segment is, for example, produced individually while, in the caseof a larger injection molding machine, ten segments can, for example, beproduced simultaneously.

After the requisite length has been reached, the handrail strip 1 can bejoined together to form an endless loop by placing the two ends of thesteel cables 3 simultaneously in the corresponding mold or in aplurality of molds and embedding them in the segments by injecting thethermoplastic elastomeric material. After the segments have cooled, theends of the steel cables are firmly connected to one another. To ensurethat no moment on the steel cables can arise in the respective region ofoverlap of the steel cables when a tensile force is applied, both endsof the steel cables lie in one plane. If, for example, in FIG. 1, thesteel cables 3 are regarded as ends, the other ends would be insertedprecisely in the spaces 12 between the steel cables 3.

It is nowadays possible to obtain thermoplastic elastomers of very greathardness, making it possible to dispense with the otherwise customarytextile reinforcements for a handrail strip manufactured from thesematerials. This considerably simplifies the structure of the handrailstrip.

When using the injection molding method, it is possible to achievesignificantly narrower manufacturing tolerances than with conventionalvulcanizable rubber blends and a better handrail strip quality can beexpected as a result. The injection molding method furthermore gives anexcellent surface finish and the handrail strip is thus of good qualityfrom the visual aspect as well. The same applies to color grades, whichcan be maintained with very great precision.

It is furthermore possible to print on the segments produced from thethermoplastic elastomers and they can thus also be used as advertisingmedia.

Virtually all thermoplastic elastomers, such as polyurethanes, elastomerblends, copolyesters and the like, are suitable as a productionmaterial.

The steel cables 3 embedded in the segments 5, 6, 7 are preferablyproduced from stainless steel or subjected to a surface treatment toensure that they do not rust. As an alternative, the steel cables canalso be coated with a thermoplastic elastomer.

Handrail strips produced from thermoplastic elastomers also have verylittle impact on the environment upon disposal since the thermoplasticmaterial can be recycled.

The process is extremely sparing of energy in comparison withconventional vulcanized handrail strips, since neither high pressuresnor relatively high temperatures have to be maintained for prolongedperiods.

As a departure from the illustrative embodiment depicted in FIGS. 1 and2, it is also possible to provide the handrail strip with differentconstructional features. In the illustrative embodiment depicted in FIG.3, the handrail strip 13 is made up of segments 14, 15, 16 which, as inthe illustrative embodiment depicted in FIGS. 1 and 2, consist of athermoplastic elastomer. The segments 14, 15, 16 are injection molded inclosely packed succession around steel cables 3, which serve as tensilesupports in the handrail strip 13.

At each of the two ends, the segments 14, 15, 16 have a projecting lip17 and 18 respectively, the lips 17 and 18 of two adjacent segmentsresting closely against one another. Thus, for example, the lip 17 ofsegment 15 rests against the lip 18 of segment 14, while the lip 18 ofsegment 15 rests against the lip 17 of segment 16. With the steel cables3 stretched, the lips rest against one another under prestress and theinterspaces 19 between the individual segments are thus tightly bridged.

The production process is performed in the same way as in the case ofthe illustrative embodiment in accordance with FIGS. 1 and 2. In order,however, to ensure that the lips 17 and 18 rest against one anotherunder prestress when the steel cables are stretched, the steel cables 3are, for example, bent during the injection molding of the segments. Inthe stretched condition of the steel cables 3, the lips 17 and 18 of thesuccessive segments then automatically rest against one another underprestress.

Alternatively, the lip 18 of the already finished segment 15 can, forexample, also be pressed against segment 15 while segment 16 with itsopposite lip 17 is being produced by injection molding. After segment 16has been finished, the lip 18 of segment 15 is released again and thetwo adjacent lips 17 and 18 thus then necessarily rest against oneanother under prestress.

In all embodiments of the handrail strip 1 and 13, respectively, thetensile supports or steel cables 3 should be under pretension, thusensuring that the segments rest closely against one another and, at thesame time, that all the cables 3 help to bear the load.

Given appropriate pairing between the materials of the segments and thefixed guideway on which the handrail strip formed by the segmentsslides, no measures need be taken to improve the sliding properties.However, it would be possible to form knobs in the shape of sphericalcaps on the inner side of the segments in order to reduce friction andthese could readily be produced in a single operation during theinjection molding of the segments. As an alternative, it would also bepossible, as in conventional handrail strips, to use textile innerlayers placed in the mold before injection molding.

LIST OF DESIGNATIONS

1--Handrail strip

2--Gripping region

3--Steel cable

4--Sliding regions

5--Segment

6--Segment

7--Segment

8--Tongues

9--Recesses

10--Upper sides

11--Gap

12--Spaces

13--Handrail strip

14--Segment

15--Segment

16--Segment

17--Lip

18--Lip

19--Interspaces

What is claimed is:
 1. A handrail strip (1) comprising a plurality ofindividual hand grip segments (5, 6, 7; 14, 15, 16) in substantiallyend-to-end contiguous longitudinally aligned relationship to each other;at least one relatively long tensile supporting means (3) formaintaining said hand grip segments generally in said end-to-endcontiguous longitudinally aligned relationship, surface means of saidhand grip segments molded in situ upon and in intimate contacting andsurrounding relationship to said supporting means (3) for holding saidhand grip segments (5, 6, 7; 14, 15, 16) secured to said supportingmeans (3), each of said hand grip segments having upper surfacescontoured to collectively define a continuous gripping plane along thetotal length of said handrail strip for generally unobstructed grippingthereof by the hand of a user, and surface means for effecting theguiding of said hand grip segments along an associated support.
 2. Thehandrail strip as defined in claim 1 wherein each of said hand gripsegments (5, 6, 7; 14, 15, 16) is formed of syntheticpolymeric/copolymeric thermoplastic material.
 3. The handrail strip asdefined in claim 1 wherein each of said hand grip segments is blowmolded in situ upon said supporting means.
 4. The handrail strip asdefined in claim 1 wherein each of said hand grip segments is injectionmolded in situ upon said supporting means.
 5. The handrail strip asdefined in claim 1 wherein said hand grip segments have axially oppositeend portions, and end portions of adjacent hand grip segments are inoverlapping relationship to each other.
 6. The handrail strip as definedin claim 1 wherein said hand grip segments have axially opposite endportions, end portions of adjacent hand grip segments are in overlappingrelationship to each other, and said end portions of each hand grip aredefined by opposite tongues and recesses.
 7. The handrail strip asdefined in claim 1 wherein said hand grip segments have axially oppositeend portions, end portions of adjacent hand grip segments are inoverlapping relationship to each other, and said end portions of eachhand grip are defined by oppositely directed tongues.
 8. The handrailstrip as defined in claim 1 wherein said hand grip segments have axiallyopposite end portions, end portions of adjacent hand grip segments arein overlapping relationship to each other, said end portions of eachhand grip are defined by oppositely directed tongues, and tongues ofadjacent hand grip segments are in abutting deformed engagement witheach other.
 9. The handrail strip as defined in claim 1 wherein oppositeend portions of adjacent hand grip segments are in abutment with eachother, and said tensile supporting means (3) defines a closed loop underpretension thereby assuring intimate abutment of adjacent hand gripsegments and portions.
 10. The handrail strip as defined in claim 1wherein said tensile supporting means (3) is a closed loop having endportions embedded in one of said hand grip segments.
 11. The handrailstrip as defined in claim 10 wherein said closed loop is underpretension thereby assuring intimate abutment of adjacent hand gripsegments end portions.
 12. The handrail strip as defined in claim 11wherein each of said hand grip segments (5, 6, 7; 14, 15, 16) is formedof synthetic polymeric/copolymeric thermoplastic material.
 13. Thehandrail strip as defined in claim 11 wherein each of said hand gripsegments is blow molded in situ upon said supporting means.
 14. Thehandrail strip as defined in claim 11 wherein each of said hand gripsegments is injection molded in situ upon said supporting means.